Coating Bronze

Question:

I sell maintenance and industrial coatings. One of my good customers has a building restoration business. and asked which coating system would be most suitable for a bronze statue with exterior exposure in the North East US. The statue is 100 years old and has been painted with various coatings over the years. They stripped off all the old paint down to the substrate. I suggested a Zinc Chromate Wash Primer which consists of a Polyvinyl butyral resin and Phosphoric Acid solution topcoated with a solvent based acrylic enamel would be most suitable. Can you comment? B. O.

Answer:

The bronze statue will last another 100 years, but neither finish system will last that long. However, both will have to recoated every few years. To protect the bronze from the effects of weather and air pollution in the Northeast United States, your suggested heavy duty finish system is the best for maximum longevity.

It is important to note the DOD-P-15328 and any other phosphoric acid activated vinyl wash primer must be applied to clean bare metal. To develop maximum adhesion, the acid activated paint must contact bare metal. Therefore, the bronze must be free from oily soils, corrosion products and old paint. Before priming, the bronze must be degreased, washed with be acid (muriatic acid should work), rinsed with clear water and dried.